Miettinen Tatu A, Gylling Helena, Viikari Jorma, Lehtimäki Terho, Raitakari Olli T
Department of Medicine, Division of Internal Medicine, University of Helsinki, Biomedicum Helsinki, Helsinki, Finland.
Atherosclerosis. 2008 Sep;200(1):177-83. doi: 10.1016/j.atherosclerosis.2007.11.028. Epub 2008 Feb 21.
Surrogate serum markers of cholesterol synthesis (e.g. squalene, lathosterol) and absorption (e.g. cholestanol, campesterol) were studied in adolescent boys to show whether homeostasis of cholesterol metabolism is maintained in different age cohorts and within different absorption levels.
In random population samples of 12- (n=162), 15- (n=158), and 18- (n=148) year-old boys participating in Cardiovascular Risk in Young Finns Study serum sterols and squalene were measured with gas-liquid chromatography at baseline, and expressed as ratios to cholesterol. Quartiles of cholestanol indicating low to high cholesterol absorption were defined from whole population.
Age-dependent decrease of serum cholesterol was associated with increased synthesis and decreased absorption of cholesterol (e.g. campesterol 205+/-6 vs. 176+/-4 in 12- vs. 18-year-old, p<0.05). In whole population, synthesis and absorption markers were interrelated indicating maintenance of homeostasis of cholesterol metabolism. Synthesis markers decreased and those of absorption increased linearly from first (low absorption) to fourth cholestanol quartile (high absorption). Correlation between synthesis and absorption, however, was significant in the lowest quartile only (lathosterol vs. campesterol, quartile 1, r=-0.283, p<0.05; quartile 4, r=-0.070, NS).
Even though cholesterol absorption and synthesis are usually changed in opposite directions, in cases with high absorption the maintenance of homeostasis of cholesterol metabolism can be lost, so that synthesis and absorption of cholesterol are changed independently of each other.
对青少年男性体内胆固醇合成（如鲨烯、羊毛甾醇）和吸收（如胆甾烷醇、菜油甾醇）的替代血清标志物进行研究，以确定在不同年龄组以及不同吸收水平下胆固醇代谢的稳态是否得以维持。
在参与“芬兰青年人心血管风险研究”的12岁（n = 162）、15岁（n = 158）和18岁（n = 148）男性的随机人群样本中，于基线时采用气液色谱法测量血清甾醇和鲨烯，并将其表示为与胆固醇的比值。根据整个人群确定了指示胆固醇吸收从低到高的胆甾烷醇四分位数。
血清胆固醇随年龄的降低与胆固醇合成增加及吸收减少相关（如12岁与18岁男性相比，菜油甾醇分别为205±6和176±4，p<0.05）。在整个人群中，合成和吸收标志物相互关联，表明胆固醇代谢稳态得以维持。从第一个（低吸收）到第四个胆甾烷醇四分位数（高吸收），合成标志物降低，吸收标志物呈线性增加。然而，合成与吸收之间的相关性仅在最低四分位数中显著（羊毛甾醇与菜油甾醇，四分位数1，r = -0.283，p<0.05；四分位数4，r = -0.070，无显著性差异）。
尽管胆固醇吸收和合成通常呈相反方向变化，但在高吸收情况下，胆固醇代谢的稳态可能丧失，从而使胆固醇的合成和吸收相互独立地发生变化。
